How to use this calculator

Use this calculator to determine reverb and delay timings. Here's how:
  1. Enter the BPM.
  2. Choose the note you want to calculate the duration of.
  3. Select the type of note - regular, dotted, or a triplet. Choosing triplet outputs the duration of one note, not the entire set of 3.
  4. Click “Calculate” and the answer will be shown.

Be sure to use a quarter note as the basis for tempo, otherwise the duration will be off. 

How to use the results with delay and reverb

 This calculator makes it easy to perfectly sync reverb and delay timings in your music.
Using This Calculator With Delay

Determine what note you want to set as your delay length and use the calculator to determine the precise duration in ms. When setting up your delay, simply use that value as the time.

For example, at 100 BPM an eighth note is 300 ms long. Set your delay to 300 ms to achieve perfect sync.
Using This Calculator With Reverb

With reverb you will apply the BPM to ms calculation to pre-delay and decay time.

With pre-delay, first determine the duration of a very short note. For example, at 120 BPM a thirty second note has a duration of 62.5 ms. If you set your pre-delay to 62.5 ms it will be exactly one thirty second note long.

The exact same principle applies with decay except that you need to subtract any pre-delay from the decay value. Here’s how that works: Let's say you want your decay to last the duration of one eighth note, which at at 120 BPM is 250 ms long. If your pre-delay is a thirty second note (62.5 ms), you will subtract these two numbers to get the correct duration of the decay.

Decay length with pre-delay = 250 ms – 62.5 ms = 186.5 ms


Understanding BPM to ms


To convert from BPM to ms we first need to determine how many ms are in a minute.

1 minute = 60 seconds = 60,000 milliseconds

Divide 60,000 by the BPM to get the duration of a single beat – a quarter note. If our BPM is 100 we can write:

Quarter note duration = 60,000 / 100 = 600 ms.

From here we can multiply or divide to find the duration of other notes. For example, a half note is twice the duration of a quarter note.

Half note duration = 600 ms x 2 = 1,200 ms

A sixteenth note is half as long as an eighth note, which is half as long as a quarter note.

Eighth note duration = 600 ms / 2 = 300 ms

Sixteenth note duration = 300 ms / 2 = 150 ms

You could also divide the duration of a quarter note by 4 to achieve the same result.

Sixteenth note duration = 600 ms / 4 = 150 ms

Calculating dotted notes and triplets works in the exact same way, except we multiply the answers by 1.5 for a dotted note and 0.6667 for a triplet.

Dotted quarter note duration = 600 ms x 1.5 = 900 ms

Duration of one third of a quarter note triplet = 600 ms x 0.6667 = 400 ms